Lab-on-a-valve or other diagnostic systems that use microfluidic components to carry out real-time analysis of biological samples have great potential for applications in a broad range of scientific research and diagnostic applications. Key to the function of such systems are methods for directing fluids to correct segments of a device, particularly a microfluidic device.
The devices and methods described herein provide effective ways of transporting fluids and/or isolating one or more analyte therefrom. Such devices can be utilized for mixing or metering fluids to perform, for example, chemical or biochemical purification, synthesis and/or analysis. The subject devices can be employed to evaluate a sample to determine whether a particular analyte, such as an organism is present in the sample. Fluidic devices can be employed to provide a positive or negative assay result. Such devices can also be employed, for example, to determine a concentration of the analyte in the sample or other characteristics of the analyte.
Fluidic devices are also specifically applied in biological assays. Devices can be employed in the capture of analytes from solution, such as by filtration. Such capture can include concentrating analytes by passing the analytes in solution over a porous solid support, selective matrix or membrane. The selective element in turn restricts the movement of the analytes away from the selective element without restricting movement of the remaining solution. One practical application of analyte capture is the concentration of nucleic acids by filtration into volumes that are amenable to amplification reactions. In such a circumstance, analytes having even a small initial concentration can be captured from a solution and thereby concentrated. The described single axis actuation valve device reduces the cost and complexity of the instrument compared to common existing valves. Further, the integration of zero, one, or multiple flow channels and/or porous solid supports in the rotor eases the requirements on fluidic layout and simplifies the design of the overall device compared to common existing valves.
Additional, fluidic devices having moving parts may suffer structurally from storage. For example, a flexible material such as a gasket that is compressed for extended periods of time during storage or shipping may become deformed and/or can experience a loss in elasticity. Further extended storage under compression can lead to adhesion of the flexible material to the compressing surface. Such circumstances can negatively affect the operability of a valve, for example, to contain, direct and/or transport fluids therethrough. Adhesion of the gasket can impede movement of the valve requiring significant force to actuate the valve or, in some cases, seize and render the valve inoperable. The subject devices and methods including a storage configuration in which a displaceable spacer holds the rotor away from the stator until the device is activated. As such, a storage configuration avoids problems with compression set and valve degradation from storage under pressure. Accordingly, the subject valve eases the requirements on the gasket elastomer sealing surface and thereby enables a higher pressure rating, and longer operating and storage lifetimes than common existing valves.